Safe or Effective?

One of the crucial ideological divisions between Chareidi Orthodoxy and Modern Orthodoxy stems from the question of whether it is better to be safe or effective.  Modern Orthodoxy maintains that in order to positively influence other Jews, we must associate with them; Chareidi Orthodoxy points to the potential pitfalls of such associations.  Modern Orthodoxy maintains that in order to fulfill Yeshayahu's designation as "a light unto the nations," we must interact with the outside world; Chareidi Orthodoxy points out the inherent dangers of such interaction.  Modern Orthodoxy claims that secular disciplines enhance our understanding of Torah; Chareidi Orthodoxy points to the corruption that may result from absorbing secular material.  The debate is not whether these pursuits are effective, but whether it is worth sacrificing spiritual safety for their effectiveness.  Chareidim downplay the value of these pursuits, while Modern Orthodox downplay their danger; but these are merely attempts to avoid the real issue - whether it is better to be safe or effective.
How do we live and how do we train our children to live?  Do we attempt to make a positive difference in the world by changing the status quo, or by doing our best within the security of established norms?  How do we live, and, more importantly, how ought we live?